Test Description

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2) - This step determines if the air temperature door position is within the specified range of the commanded value.
4) - Tests for the proper operation of the circuit in the low voltage range.
5) - Tests for the proper operation of the circuit in the high voltage range. If the jumper fuse opens when you perform this test, then the signal circuit contains a short to ground.
6) - Tests for a short to voltage in the 5-volt reference circuit.

Fig 1: DTC B0229 Diagnosis (Steps 1-7)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC B0229 Diagnosis (Steps 8-13)

Courtesy of GENERAL MOTORS CORP.